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Peter Wothers describes the lure of the large-scale chemistry experiment

Peter Wothers describes the lure of the large-scale chemistry experiment

No-one is bored by a really big explosion. That was the headline premise behind The Big Experiment, a newly-launched TV series I had the experience of being filmed in last year alongside Cambridge University lab technician Chris Brackstone and physicist Laura Grant from Liverpool University.

The programme-makers’ challenge was to get a group of nineteen underprivileged and disinterested 14-year olds from East London turned on to science. With our combined experience of teaching and outreach science, we devised a syllabus connected by large-scale experiments to show the children how exciting science can be, and that it is relevant to their lives. We had just six weeks to get them through their national science exams - a full 18 months early.

The teenagers thought they hated science; they found it boring, and they constantly disrupted their lessons. The most polite of them explains to viewers: ’The bits of science I like least are physics, chemistry and biology.’ They hadn’t been trusted to take part in practicals - but if their classroom behaviour was bad, most frustrating of all was their disinterested attitude: it wasn’t cool to appear interested in anything to do with school, let alone science, in front of their peers.

Of course flashes, whizzes, and bangs did spark their interest. It was genuinely exciting to see them, sometimes, drop their air of indifference as they got drawn into the practical chemistry. One experiment that got the whole class inspired was posing next to a theatre wall lined with phosphorescent paper. After a bright flash of magnesium powder and an enormous billow of smoke - which set off the fire alarms - we had a glowing green wall decorated with silhouettes where bodies had blocked out the light. To teach them that hydrogen is a flammable gas, we had them blowing up hydrogen balloons in the teaching laboratory, seeing the flames and feeling the heat. Reading it in a textbook doesn’t compare.

The television budget allowed us to set up some extraordinary large-scale experiments around London (the ’big experiments’ of the show’s title). We had students inside a phone box, struck by an electric discharge from a Tesla coil (quite safe: the metal surround conducts electricity to the earth); they stuck themselves high up on a crane with a polymer-based glue; and flew out of the window on helium balloons. But even heating up copper carbonate and bubbling the gas that came off through lime-water was rated ’amazing’.

Teachers don’t have the freedom, timetable flexibility or resources to do all the experiments we covered. Nor are they necessarily specialists in every science. I can see how someone with a biology degree might feel less comfortable with physical science practicals. But teachers still need to be creative and inventive: there are plenty of fun experiments to do, and it needn’t all be large-scale.

What about the supposed dangers of school practical work? Health and safety precautions don’t actually preclude any of the experiments that teachers perceive as too dangerous for the classroom - they just need the proper risk assessments beforehand. Any school could do the small hydrogen balloon experiments that we did. The list of banned chemicals is actually very small indeed. As we’ve found, the important thing is to build up trust with students so that they don’t misbehave with chemicals. We trust children to go into a woodwork or metalwork class and use a drill or a knife, after all - they have learnt that knives are dangerous and treat them with respect. They just have to learn that sulfuric acid, which looks just like water, must also be treated with respect.

What really inspired the children was making discoveries for themselves, not sitting back and listening to someone else tell them about it. ’I’m in the top set for science now. Of course, it’s nothing to do with what you did,’ one student told me after the series.

Peter Wothers is at Cambridge University, UK. ’The Big Experiment’ is now on The Discovery Channel, Thursdays, 9pm. More details see website.